Door-releasing mechanism.



A. J. ANDEHSSON & H. E. 005mm.

DOOR RELEASING MECHANISM.

APPLICATION FILED APR. 8. I918.

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A. J. ANDERSSON & H. E. COBURN.

DOOR RELEASING MECHANISM.

APPLICATION FILED APR. s. 1918.

Patented Dec. 10, I918.

2 SHEETS-SHEET 2 Nm/ a l ill I'll QN kw IIIWI/l/l/llllI/ll WE??? NE W v a Iff/lflf' ll 6 ALBIN J. ANDERSSON AND 'HENRY E. COBUBDLOF WORCESTER, MASSACHUSETTS; SAID COBURN ASSIGNOR TO SAID ANDEBSSON.

noon-antnasme MECHANISM.

Specification of Letters Patent.

Fatented Dec. 10, 1918.

Application filed April 8, 1918. Serial 'No: 227,235.

This invention relates to a door releasing,

mechanism particularly designed for doors used exclusively as emergency exits.

It is the general object of our invention to provide door releasing mechanism which shall positively lock the doors at all times so that they cannot be opened from the outside, but which will. open the doors automatically whenever the door is approached by persons on the inside thereof.

With this general object in view, important features of our invention relate to the provision of improved devices for securing and releasing emergency doors, which mechanism is put in operation by the weight of a person approaching the doors from the inside.

Another important feature of our invention relates to the provision of additional manually operated devices available to release the doors if for any reason the automatic release fails to operate.

Other features of our invention relate to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the ap pended claims.

A preferred form of our invention is shown in the drawings, in which Figure 1 is a plan view of our improved mechanism, the platform being partially broken away;

Fig. 2 is a sectional elevation taken along the line 22 in Fig. 1;

Fig. 3 is a detail elevation taken along the line 33 in Fig. 1;

Fig. 4 is a detail elevation looking in the direction of the arrow 4 in Fig. 2;

Fig. 5 is an elevation of the manually releasing mechanism;

Fig. 6 is a detail sectional plan view taken along the line 6-6 in Fig. 5, and

Fig. 7 is a detail sectional elevation taken along the line 77 in Fig. 5.

Referring to the drawings, we have shown d r l0 and 11 each pivo ed to swing outward about its more remote vertical edge. The structure in which the doors are mounted is indicated by the numeral 12 and is preferably of fire-proof material. The doors are provided with recesses or pockets 13 on their inner sides near their'lower adjacent corners. A latch plate 14 extends across the lower part of each pocket, which plate may be firmly secured to the doors by bolts 15 (Fig. 1) or may be of the releasable type hereinafter described.

The plates 14 are engaged by hooks 16 formedon the ends of locking levers 17 pivoted on a shaft 18 secured in brackets 19 mounted on the structure 12. A platform 20 is supported above thelevers 17 the platform being provided with bearings 21 (Fig. 3) pivoted on shafts 22 supported in brackets 23 secured to the structure 12, the shafts 22 being adjacent the front or outer edge of the platform 20. The inner or rear edge of the platform 20 rests upon a cross piece 24 which connects the inner ends of the two levers 17. A stop 25 limits the downward movement of the platform 20.

Compression springs 26 are interposed between the front end of each lever, 17, and the underside of the platform 20, these springs normally holding the hooks 16 in engagement with the latch plates 14. Spring plungers 27 are mounted in casings 28 secured to the underside of the platform, one of said plungers engaging the inner face of each door. As these emergency exits are quite commonly used at the foot of emergency Stairways, we have indicated a portion of such a stairway at 30 in Fig. 2.

Considering the mechanism thus far described, the operation is as follows: The springs 26 are of such strength that the hooks l6 normally engage the plates 14 and hold the doors 10 and 11 in closed position, the inner end of the platform 20 being raised above the stop 25 by the levers 17. In case of fire or other emergency a person descending the stairway 30 and approaching the doors will step upon the inner portion of the platform 20 and depress the same, overcoming the pressure of the Springs 26, and raising the hooks 16 to release the doors. As soon as the doors are released, the spring plungers 27 pressing against the inner faces of the doors force the doors outward, thus permitting free passage from the stairway, The stop 25 limits downward movement of the platform 20 so that the mechanism cannot be disarranged no matter how many persons are supported by the platform 20. When the weight is removed from the platform and the doors are closed, the parts immediately resume their initial posit1on.

Under all ordinary circumstances, the

mechanism thus far described is perfectly reliable and satisfactory. It is possible, however, that some obstruction may accidentally be placed beneath the platform 20, thus preventing the operation of the mechanism above described- In order to permit exit under such circumstances we have shown in Figs. 5, 6 and 7 additional mechanism for manually releasing the doors under these conditions. In this construction each fixed latch plate 14 is replaced by a pivoted latch plate 31 hinged to a plate 32 which in turn is bolted to the inner face of the door. 'A bar 33 is mounted to slide vertically in bearings 34:, 35 and 36 fixed to the door 10 or-11, and the lower end of the bar 33 normally covers the swinging end of the latch plate 31, preventing the plate from swinging inwardly.

A hand lever 37 is pivoted to the door at 38 and is pivotally connected at 39 to the bar 33. If the platform 20 fails to release the hooks 16 the levers 37 may be opera-ted to raise the sliding bars 33 out of the path of the swinging latch plates 31. These plates then swing freely inwardly, releasing the doors, while the lovers 17 remain in their initial position.

It will be seen therefore that we have provided simple and reliable mechanism for automatically releasing the doors, and that we have also provided manually operable mechanism which may be used in case of accident to the automatic mechanism.

Having thus described our invention, it will be evident that changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of our invention as set forth in the claims, and we do not wish to be otherwise limited to the details herein disclosed, but what we claim is- 1. Door releasing mechanism comprising locking levers mounted on fixed pivots and each engaging a part carried by a door, springs to hold said levers in looking position, and a platform having a length substantially equal to the width of the door opening mounted on fixed pivots adjacent a said opening and extending from said doors a substantial distance, the outer portion of said platform being directly supported by the outer ends of said levers and being movable downwardly with said levers under increased load to thereby release said doors.

2. Door releasing mechanism comprising locking levers, sprlngs to hold said levers in looking position, a platform partially supported by said levers and movable downwardly to operate said levers when addie tional weight is placed thereon, a movable latch plate on each door engaged by one of said levers, and manual means for releasing said latch plates.

In testimony wherof we have hereunto affiXed our signatures.

ALBIN J. ANDERSSON. HENRY E. COBURN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0. 

